A regulatory loop between the fibroblast growth factors FGF-8 and FGF-10 plays a key role in limb initiation and AER induction in vertebrate embryos. Here, we show that three WNT factors signaling through beta-catenin act as key regulators of the FGF-8/FGF-10 loop. The Wnt-2b gene is expressed in the intermediate mesoderm and the lateral plate mesoderm in the presumptive chick forelimb region. ...

Concanavalin A (Con A), a tetravalent lectin, was shown to impair 8 chick embryo fibroblast (8 d CEF) spreading on a laminin (LM) substrate but not on a fibronectin substrate (FN), suggesting that cell surface Con A binding proteins could be involved in 8 d CEF spreading on a LM substrate. The interaction of Con A-binding proteins with Con A is dependent upon the carbohydrate moieties of the is...

The observation and manipulation of chicken embryos in ovo has been useful for understanding the development vertebrates. However, viability longevity are severely compromised even by simple manipulations to egg shell. We have explored experimental protocols that promote ex use an undergraduate teaching laboratory setting. Here, we demonstrate a modified windowing technique increases survival t...

Changes of cell shape resulting from cellular flattening on culture substratum have previously been demonstrated to correlate with mitotic activity of normal animal cells in monolayer cultures. Here, we compared the shapes and proliferation of chick embryo fibroblasts cultured either in multicellular, multilayered sheets extended between glass fibres, or in standard monolayers. Fibroblasts in s...

The identification of acidic and basic fibroblast growth factors (FGFs) in a number of embryonic tissue extracts has implicated these growth factors in the regulation of a variety of embryonic events including angiogenesis, eye development, and muscle differentiation. Lack of information concerning the cellular distribution of the growth factor within these tissues has made it extremely difficu...